Recently, in the medical field, surgeries conducted using a support arm device are being conducted widely. For example Patent Literature 1 discloses a medical support arm device of what is called the master-slave type, in which an arm unit with a surgical tool (surgical instrument) attached is driven by the operations of an operator (a surgeon, for example) via a controller.
On the other hand, with a medical support arm device of the master-slave type as described in Patent Literature 1, technology for detecting force acting on the surgical instrument and transmitting such force to the operator operating the controller, or in other words, technology for precisely realizing force sensing and force feedback, has not been established. One of the reasons for this is because it is difficult to install on the leading edge section of a surgical instrument a force sensor for detecting force acting on the leading edge section. For example, consider forceps used in laparoscopic surgery. Only a narrow space with a diameter of approximately 5 (mm) exists at the leading edge section of the forceps, and it is difficult to mount in this space a high-precision force sensor, such as a six-axis force sensor, for example.
Accordingly, there has been developed technology that drives the arm unit of a support arm device with a pneumatic actuator, and also estimates the force acting on a surgical instrument attached to the arm unit based on the driving force of the pneumatic actuator, thereby providing force feedback (for example, Patent Literature 2). According to this technology, the force acting on the surgical instrument may be estimated without using a force sensor, thereby making it possible to address the issue related to the installation position of a force sensor as discussed above.